1. Field of the Invention
The present invention relates to a compact zoom lens system having a zoom ratio about two to four, a small amount of chromatic aberration, and high optical performance across the entire image, suitable for a video camera and an electronic still camera using an imaging device such as a solid state imaging device.
2. Related Background Art
A lot of zoom lens systems suitable for a video camera and an electronic still camera using an imaging device such as a solid state imaging device have been proposed. Among them, the majority of the zoom lens systems having a zoom ratio about two to four is a zoom lens type having a negative lens to the most object side of the lens system. For example, there is a zoom lens system disclosed in Japanese Patent Application Laid-Open No. 11-23967.
In recent years, the number of image pixels used in a video camera and an electronic still camera using an imaging device such as a solid state imaging device has steadily been increasing. In accordance with the trend, the lens system has been requested to have higher optical performance across the entire image. In particular, the lens system has been requested to reduce flare component and chromatic aberration as well as have high optical performance in the periphery.
However, the zoom lens systems disclosed in Japanese Patent Application Laid-Open No. 11-23967 and the like have had a problem not to have sufficient ability to reduce flare component or chromatic aberration across the entire image.